Sample Problem: Earthwork Volume (Prismoidal Formula)

Achieving higher accuracy in earthwork estimation.

Example

A highway project requires excavation over a 100-meter100\text{-meter} section. The cross-sectional areas of the cut at the beginning (Station 0+0000+000) and the end (Station 0+1000+100) are A1=40 m2A_1 = 40 \text{ m}^2 and A2=60 m2A_2 = 60 \text{ m}^2, respectively. A survey taken exactly at the midpoint (Station 0+0500+050) reveals the cross-sectional area there is Am=52 m2A_m = 52 \text{ m}^2. Calculate the volume of earthwork using the highly accurate Prismoidal Formula.

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Sample Problem: Mass Haul Diagram Metrics

Calculating Free Haul and Overhaul quantities.

Example

A mass haul diagram analysis yields a balance line. Above this balance line is a massive cut/fill loop representing 10,000 cubic meters10,000 \text{ cubic meters} of total earthwork. The Free Haul Distance (FHD) specified in the contract is 500 meters500 \text{ meters}. A horizontal line of length 500 m500 \text{ m} is drawn inside the loop, intersecting the curve at two points. The volume ordinate at this horizontal 500 m500\text{ m} line is 7,000 m37,000 \text{ m}^3.
  1. Calculate the Free Haul Volume (FHV).
  2. Calculate the Overhaul Volume (OHV).

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Sample Problem: Base Course Construction Compaction

Determining if field compaction meets quality assurance standards.

Example

A crushed stone base course has a laboratory maximum dry density (MDD) of 2,150 kg/m32,150 \text{ kg/m}^3 as determined by the Modified Proctor Test. A field sand-cone test is performed on the compacted base layer. The field test determines the bulk (wet) density of the soil in place is 2,280 kg/m32,280 \text{ kg/m}^3 and the field moisture content is 8.5%8.5\%. The project specification requires a minimum relative compaction of 98%98\%. Does this section pass the compaction test?

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Case Study: Pavement Distresses (Rutting vs. Fatigue Cracking)

Diagnosing the root causes of flexible pavement failures.

Example

An engineer inspects a five-year-old asphalt highway. In the right lane (heavy truck lane), there are deep, continuous longitudinal depressions right where the wheel paths are located. In the left lane (passenger car lane), there is a network of interconnected cracks resembling the skin of an alligator. Identify these two specific types of distresses and explain their primary mechanical causes.

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Case Study: Construction Equipment Selection

Matching machinery to specific earthwork and paving tasks.

Example

A contractor has won a bid to construct a 10-kilometer10\text{-kilometer} rural highway. The project involves:
  1. Clearing dense brush and small trees.
  2. Excavating a massive hill (100,000 m3100,000 \text{ m}^3 of soil) and moving the dirt 3 kilometers3 \text{ kilometers} down the alignment to build a fill section.
  3. Placing and compacting the hot mix asphalt (HMA) surface.
Recommend the primary piece of heavy equipment best suited for each of these three specific tasks.

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